The invention relates generally to an expansion system and more specifically to an integrated cooling unit adapted for use in expansion systems.
Currently, extractive techniques are available to generate energy, such as electrical energy by utilizing working fluids. Each of these techniques is based on pressurizing, heating, and expanding a working fluid. One method of generating electrical energy from a stream of hot gas such as gas turbine or engine exhaust is to apply an organic Rankine cycle. In the organic Rankine cycle, the working fluid is pressurized and heated, and permitted to expand through the turbine generator. This expansion of working fluid may convert mechanical energy of the turbine generator into electrical energy. In one example, the expansion of the working fluid may cause rotation of a turbine wheel in the turbine generator. This rotation of the turbine wheel may further rotate a rotor inside a generator. The rotation of the rotor inside the generator, particularly a stator, is then utilized to generate electrical energy. However, while generating the electrical energy, there may be electrical and mechanical losses in the turbine generator. These electrical and mechanical losses in the turbine generator may further generate heat within the internal components such as the rotor, the bearings, and the stator of the generator. This heat needs to be discharged from the generator to prevent overheating of the internal components of the generator.
Certain currently available conventional techniques entail use of a dedicated cooling system using air, water, or oil to dissipate heat from the turbine generator into the ambient. However, the dedicated cooling system is disposed external to the organic Rankine cycle, and is configured to convey the fluids such as air, water, or oil from an external source to the turbine generator. Thus, implementing a separate cooling system with a separate cooling fluid increases the cost of manufacturing the system. Also, the cost of the cooling system is dependent upon the amount of heat to be dissipated, which in turn diminishes the efficiency of the Rankine cycle.
It is therefore desirable to develop a simple and cost effective cooling system that prevents the generator from overheating and also improves the efficiency of the cycle.